Watch Heartbreaking Tribute to Police Dog Killed in Line of Duty [VIDEO]

One of Pittsburgh's finest may be gone, but he's definitely not forgotten.

Rocco, an 8-year-old German shepherd who worked the police in Pittsburgh, died Thursday after getting stabbed while helping officers arrest a wanted sex offender earlier this week.

Authorities say the suspect attacked Rocco with a knife while the dog tried to bite him.

Rocco ended up with a stab wound that ran three inches deep into his kidney, resulting in serious blood loss. He ended up contracting pneumonia and died of his injuries.

When officers learned how grave Rocco's condition was, they showed up at the Pittsburgh Veterinary Specialty & Emergency Center. After he passed away, his body was removed from the hospital amidst a tribute the likes of which you rarely see, especially for an animal.

Rocco had served with the police department since 2008.

The suspect, who was apprehended, is now looking at new charges, including abusing a police animal, disarming a law enforcement officer, aggravated assault, burglary and misdemeanor charges of animal cruelty, resisting arrest and possessing instruments of a crime.

Rocco's death has been met with such grief that Pittsburgh's mayor has ordered flags to fly at half-mast.